1 Field of the Invention
This invention relates to lubricant additives and compositions thereof and, more particularly, to lubricant compositions comprising oils of lubricating viscosity or greases prepared therefrom containing a minor friction reducing amount of certain borated alcohols or mixtures of borated alcohols.
2 Description of the Prior Art
Many means have been employed to reduce overall friction in modern engines, particularly automobile engines. The primary reasons are to reduce engine wear, thereby prolonging engine life, and to reduce the amount of fuel consumed by the engine, thereby reducing the engine's energy requirements or fuel consumption.
Many of the solutions to reducing fuel consumption have been strictly mechanical, as for example, setting the engines for a leaner burn or building smaller cars and smaller engines. However, considerable work has been done with lubricating oils, mineral and synthetic, to enhance their friction properties by modifying them with friction reducing additives.
Alcohols and mixtures of alcohols have been used as intermediates in the manufacture of a variety of lubricant additives. However, the use of alcohols themselves has not been widespread as engine oil additives because of potential oxidative and thermal instability and volatility difficulties. It has now been found that the borated alcohols provide friction reducing characteristics that the non-borated compositions lack; in addition, the borated derivatives improve oxidative and thermal stability, volatility and bearing corrosion inhibiting properties. These borated alcohols and borated mixtures of alcohols are, to the best of applicants' knowledge, novel and have not been used as multifunctional and/or friction reducing additives in lubricating compositions.
U.S. Pat. No. 2,160,917 discloses lubricants containing low molecular weight borate esters, e.g., borate esters containing from 4 to 12 carbon atoms. The disclosed borates include the tributyl and trilauryl borates. Other patents include U.S. Pat. No. 3,014,870 (to mixtures of amines and certain boronic mono- or diesters); U.S. Pat. No. 3,108,966 (aryl boronic esters and thio acid ester lubricants); U.S. Pat. No. 3,133,951 (fuels containing dialkyl boron esters); U.S. Pat. No. 3,347,793 (tertiaryalkyl boron esters) and U.S. Pat. No. 3,509,054 (esters or boron acids with 2,6-dialkyl-phenols).